In the section about 'alt' tags, "If a user is viewing your site on a browser that doesn't support images" sounds like something coming from a very old text. I wonder if that's still relevant for anyone. The second part of the sentence (screenreaders) taught me something, though!

Blind people still use browsers like this, it's a 508 compliant standard if nothing else.

Matt, here's a few things: - on page 4 you might mention that Google may change your title tag on the search results. - on page 8, you might mention case sensitive URLs (can cause dupe content if not used consistently) and the use of hyphens vs underscores in URLs. - on page 15, I would updated the heading "Create content primarily for your users, not search engines" so it takes out the word 'primarily'. - Page 18, would it be helpful for users to add location and tags, titles, in EXIF data in images? - Page 21, I would mention specifying xml sitemap location in robots.txt file.

This seems out of date: "Google AdWords provides a handy Keyword Tool".

You'll end up on a page explaining Keyword Planner has replaced Keyword Tool. To access the tool I must sign in to my AdWords account.

So you have to sign into your free Google AdWords account to use a feature of Google AdWords? The link still works and even explains what has changed in significant detail.

Why is it on a user content domain?

Google is pretty paranoid about hosting things under google.com unless they absolutely have to be there, since user authentication cookies are the holy grail for malware or other attacks. The published papers from research.google.com are linked off the same static.googleusercontent.com site, for example.